Surprises -- particularly good ones -- are very rare in FM transmitters these days, as the Federal Communications Commission's crackdown on overpowered radio broadcasting devices has compelled many companies to broadcast just within the U.S. government's legal limitations. Over the past year, we've become familiar enough with those limitations that it seems obvious when a device is unhappily struggling to match them or blowing right past the marks, hoping not to get caught. Though we might be wrong, XtremeMac's combination FM transmitter and car charger InCharge FM ($70) seems to be in the latter category: two sample units we tested outperformed recent FCC compliant transmitters we've tested by a fair margin.

Like the earlier InCharge Auto, InCharge FM appears to have been designed to physically match the iPhone, using chrome and black plastic in an attractive, minimalist combination for each of its key parts. First, there’s a car charging bulb with a subtle blue light to indicate that it’s receiving power, and second, there’s a cabled FM transmitter that connects to an iPod with a Dock Connector plug at one end, and a case-compatible USB plug for charging at the other. InCharge FM doesn’t run off of the iPod’s battery, and so depends on the cabled transmitter to be connected to the charging bulb, or a USB-enabled computer or wall charger, for power.

This latter point deserves a little extra attention. Virtually every one of the “in-car” FM transmitters we’ve tested over the past few years is “only in-car,” with the manufacturer assuming—probably correctly—that you’re only interested in hearing your iPod’s audio through a radio when you’re driving. Because you can pull the car charger off and connect InCharge FM to any powered USB port or wall charger, this one can be used indoors too, which will be a bonus for people who want to charge and hear their iPods through home radios without using a dock or wires. Our one and only issue with XtremeMac’s connectors was a slightly loose right lock on our second review unit’s Dock Connector, which didn’t interfere with the unit’s performance.

XtremeMac’s transmitter looks like a pill-shaped miniature iPhone, with buttons on its face and sides, plus a blue LED screen where the iPhone’s touchscreen would be. A play/pause/next track button for iPod touch and a stereo/mono toggle switch are accessible on one side of the transmitter, while the other side has two preset buttons, and the face has manual tuning buttons for the transmitter. The screen’s only for numbers, and keeps at least the bright blue decimal dot on display whenever power’s running through the transmitter, as well as matching digits whenever an iPod or iPhone is connected. The currently shipping version of InCharge FM is only iPod-compatible, bringing up the iPhone’s nag screen, but a nagless version is planned for near future release as well. Nag aside, both of the review units we tested worked extremely well with the iPhone.

In fact, the units worked extremely well with anything we connected. XtremeMac says that the InCharge FMs use a licensed FM transmission technology called Quintic PureFM that promises “a consistently clean signal and excellent dynamic range,” and though the units we tested weren’t immune to the subtle static levels that persist in all FM transmitters, they did in fact sound great—especially when tuned to everclear station 87.9FM. We preferred the dynamic sound of the InCharge FM to what we heard from Belkin’s TuneCast Auto, as well as Griffin’s most recent iTrip Auto—on good or bad stations, XtremeMac’s transmitter sounded clearer.

To quantify this a bit more, on an empty FM station such as 87.9FM, InCharge FM sounded almost completely clear, which wasn’t a shock, but it also had the ability to basically flood out an existing station that was weak to moderate on the dial, and didn’t suffer as much from the transmitter’s location in our test vehicle as the others. We were also able to get a clear signal from five feet away from the antenna indoors. While these are positive performance characteristics that any end user would appreciate, they’re also hints that the transmitter is like a track runner on steroids, capable of outperforming its rivals but also leaving us wondering how long it would remain in competition.

Overall, we can’t help but be impressed by the overall performance and value the current version of InCharge FM brings to the table. Bucking past XtremeMac pricing trends, it sells for $10 less than its key competitors, but still manages to outperform them on sound, and look great in the process. Its ability to work indoors, using a USB charger or computer for power, also adds value for some users. From a features standpoint, all it’s conspicuously missing is Belkin’s ClearScan or Griffin’s SmartScan auto-tuning feature, and then, its inclusion of near-universally-empty 87.9FM on the dial all but eliminates the need for tuning. As reviewed, InCharge FM merits our high overall recommendation; however, should performance of later units change for the worse, our rating may be revised.

Editors' Note: iLounge only reviews products in "final" form, but many companies now change their offerings - sometimes several times - after our reviews have been published.
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